Ensure slices are zeroed (#3407)

database/batch.go

@@ -75,6 +75,7 @@ func (b *BatchOps) Size() int {
 }
 
 func (b *BatchOps) Reset() {
+	clear(b.Ops)
 	b.Ops = b.Ops[:0]
 	b.size = 0
 }

database/encdb/db.go

@@ -204,6 +204,7 @@ func (b *batch) Reset() {
 	if cap(b.ops) > len(b.ops)*database.MaxExcessCapacityFactor {
 		b.ops = make([]database.BatchOp, 0, cap(b.ops)/database.CapacityReductionFactor)
 	} else {
+		clear(b.ops)
 		b.ops = b.ops[:0]
 	}
 	b.Batch.Reset()

database/prefixdb/db.go

@@ -313,6 +313,7 @@ func (b *batch) Reset() {
 	if cap(b.ops) > len(b.ops)*database.MaxExcessCapacityFactor {
 		b.ops = make([]batchOp, 0, cap(b.ops)/database.CapacityReductionFactor)
 	} else {
+		clear(b.ops)
 		b.ops = b.ops[:0]
 	}
 	b.Batch.Reset()

utils/set/sampleable_set.go

@@ -108,9 +108,7 @@ func (s *SampleableSet[T]) Remove(elements ...T) {
 // Clear empties this set
 func (s *SampleableSet[T]) Clear() {
 	clear(s.indices)
-	for i := range s.elements {
-		s.elements[i] = utils.Zero[T]()
-	}
+	clear(s.elements)
 	s.elements = s.elements[:0]
 }
 

utils/zero.go

@@ -4,16 +4,6 @@
 package utils
 
 // Returns a new instance of a T.
-func Zero[T any]() T {
-	return *new(T)
-}
-
-// ZeroSlice sets all values of the provided slice to the type's zero value.
-//
-// This can be useful to ensure that the garbage collector doesn't hold
-// references to values that are no longer desired.
-func ZeroSlice[T any](s []T) {
-	for i := range s {
-		s[i] = *new(T)
-	}
+func Zero[T any]() (_ T) {
+	return
 }